Francis, who was inaugurated as the new head of the world's 1.2 billion Catholics on Tuesday, has made some changes since taking the helm -- most notably by adopting a simpler, personal style and calling for the church to focus on serving the poor and needy.

The new pontiff was flown to Castel Gandolfo by helicopter for the lunch date.

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He was greeted at the helipad by Benedict XVI, and the pair exchanged an embrace, Vatican spokesman the Rev. Federico Lombardi said. They then rode in a car together to the Castel Gandolfo residence.

Both men wore simple white cassocks, but only Francis wore the white papal mantle and sash over his robe.

The two then prayed together side-by-side in a chapel before meeting in a library at the residence for 45 minutes of talks ahead of lunch.

Photos:Photos: Pope Francis

Photos:Photos: Pope Francis

Pope Francis – Before becoming Pope Francis, he was Argentinian Cardinal Jorge Mario Bergoglio, the former archbishop of Buenos Aires. The announcement for the selection of a new pope came on Wednesday, March 13, the first full day of the cardinals' conclave in the Sistine Chapel.

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Pope Francis – Bergoglio arrives for the congregation meeting at Synod Hall in the Vatican on March 7.

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Pope Francis – Bergoglio, right, draws the cross on the forehead of a parishioner during a Mass for Ash Wednesday, which begins the 40-day period of abstinence for Christians before the Holy Week and Easter, on February 13 at the Metropolitan Cathedral in Buenos Aires.

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Pope Francis – Bergoglio says a Mass in honor of the late ex-President Nestor Carlos Kirchner on October 27, 2010, in Buenos Aires.

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Pope Francis – During a Mass against trafficking in July 12, 2010, in Buenos Aires, Bergoglio speaks.

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Pope Francis – Bergoglio delivers his homily at the church of St. Cajetan in Buenos Aires on August 7, 2009.

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Pope Francis – Then-Archbishop of Buenos Aires Bergoglio is seen in Vatican City in this undated photo. He's the first non-European pope in the modern era and the first South American pope.

Pope Francis personally greets crowds

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Video footage released by the Vatican after Francis had returned to Vatican City showed the two men warmly clasping hands as they greeted each other.

Benedict, who walked with the aid of a stick, looked frail and moved slowly as they entered the chapel to kneel together.

Relations between Francis and his predecessor were warm and cordial, said Lombardi. Francis presented Benedict with the gift of a painting he said reminded him of the former pontiff's gifts to the church.

Lombardi declined to tell reporters what the pair discussed in the library, saying only that they were private talks.

Vatican observers believe that one item on the agenda was the contents of a 300-page dossier presented by three cardinals to Benedict in the wake of the Vatileaks scandal.

Benedict passed on the report -- ordered after leaks last year revealed claims of corruption within the Vatican hierarchy -- to his successor.

Italian media reports suggested the cardinals had uncovered a series of scandals involving sex, money and power, but the Vatican press office sought to tamp down what it called a rash of "often unverified, unverifiable or completely false news stories."

The pair may also have talked about possible appointments by Francis. The people he chooses to hold key roles may give an indication of his priorities for the church at a time when some are calling for reform and modernization of its hierarchy.

They have spoken several times by telephone since Francis was elected 10 days ago, but this was their first face-to-face meeting, the Vatican said.

Crowds who had gathered in the small town's central square waved and clapped as the white papal helicopter twice passed overhead before landing. Some chanted "Francesco, Francesco" -- the pope's name in Italian.

According to police at Castel Gandolfo, the crowds numbered between 1,500 and 2,000.

Many had gathered in the hope of seeing Francis appear at a balcony to wave, but they were disappointed.

Life of seclusion

Francis was elected on March 13 after Benedict became the first pope in nearly 600 years to resign, citing age and frailty. A new pope usually takes the reins only following the death of his predecessor.

The hilltop castle overlooking a lake is the summer papal residence and has been home to Benedict since he left Vatican City on February 28.

Benedict's last public appearance was at a window of the castle, when he blessed the crowds below before retiring into seclusion.

The pope emeritus is expected to move back to Vatican City at the end of April, once restoration work on a small monastery within its grounds is complete. There, he will devote himself to prayer and study.

Benedict "has attentively followed the events of recent days," including Francis' inauguration Mass before crowds of well wishers and dignitaries, the Vatican said.

When the last pope to resign, Gregory XII, stepped down in 1415 it was to help resolve the worst institutional crisis in the church's history -- a schism that had led to three rival claimants to the papacy.

And when former hermit Pope Celestine V resigned in 1294 after less than six months in office, he was imprisoned soon afterward by his successor, Pope Boniface VIII.

On Friday, he met with the Vatican diplomatic corps and thanked them for the work they do to "build peace and construct bridges of friendship and fraternity" with some 180 states around the world.

"Through you I encounter your peoples, and thus in a sense I can reach out to every one of your fellow citizens, with their joys, their troubles, their expectations, their desires," he said.

The coming week, which leads up to Easter Sunday, will be a busy one for the new pontiff, starting with Palm Sunday Mass.

On Thursday, Francis will break with tradition by celebrating the Mass of the Lord's Supper -- which is centered on the gesture of the washing of feet -- at the Casal del Marmo youth detention center, the Vatican said.

The service has in past years been held at the grand Basilica of St. John Lateran, the official seat of the bishop of Rome.

"In his ministry as Archbishop of Buenos Aires, Cardinal Bergoglio used to celebrate the Mass in a prison or hospital or hospice for the poor and marginalized," the Vatican said in a statement.

"With this celebration at Casal del Marmo, Pope Francis will continue his custom, which is characterized by its humble context."

It will not be the first time Francis visits the prison. He was there in March 2007 to celebrate Mass.